Emit unfinished handler warnings separately for cancellation

Author: dandavison

temporalio/worker/_workflow_instance.py

@@ -429,15 +429,20 @@ def activate(
                     f"Failed converting activation exception: {inner_err}"
                 )
 
-        def is_completion(command):
+        def is_non_cancellation_completion(command):
             return (
                 command.HasField("complete_workflow_execution")
                 or command.HasField("continue_as_new_workflow_execution")
                 or command.HasField("fail_workflow_execution")
-                or command.HasField("cancel_workflow_execution")
             )
 
-        if any(map(is_completion, self._current_completion.successful.commands)):
+        # We do also warn in the case of workflow cancellation, but this is done
+        # when handling the workflow cancellation, since we also cancel update
+        # handlers at that time.
+        if any(
+            is_non_cancellation_completion(c)
+            for c in self._current_completion.successful.commands
+        ):
             self._warn_if_unfinished_handlers()
 
         return self._current_completion
@@ -1851,6 +1856,7 @@ async def _run_top_level_workflow_function(self, coro: Awaitable[None]) -> None:
                 err
             ):
                 self._add_command().cancel_workflow_execution.SetInParent()
+                self._warn_if_unfinished_handlers()
                 # Cancel update tasks, so that the update caller receives an
                 # update failed error. We do not currently cancel signal tasks
                 # since (a) doing so would require a workflow flag and (b) the

tests/worker/test_workflow.py

@@ -5584,9 +5584,16 @@ class _UnfinishedHandlersOnWorkflowTerminationTest:
     async def test_warning_is_issued_on_exit_with_unfinished_handler(
         self,
     ):
-        assert await self._run_workflow_and_get_warning() == (
-            self.handler_waiting == "-no-wait-all-handlers-finish-"
-        )
+        warning_emitted = await self._run_workflow_and_get_warning()
+        if self.workflow_termination_type == "-cancellation-":
+            # All paths through this test for which the workflow is cancelled result
+            # in the warning being emitted.
+            assert warning_emitted
+        else:
+            # Otherwise, the warning is emitted iff the workflow does not wait for handlers to finish.
+            assert warning_emitted == (
+                self.handler_waiting == "-no-wait-all-handlers-finish-"
+            )
 
     async def _run_workflow_and_get_warning(self) -> bool:
         workflow_id = f"wf-{uuid.uuid4()}"